1. Field of the Invention
This invention pertains to articles of manufacture utilizing a substrate treated with a chemical emulsion binder. The substrate is then dried to improve the strength and structural integrity of the substrate materials. More particularly, the present invention pertains to articles of manufacture having substrates bound with aqueous dispersions of copolymers having a backbone of recurring .alpha.-olefin and carboxylic acid monomeric units, having grafted thereto one or more polymeric grafts with the following recurring monomeric units: EQU --NHC (O) RC (O) NHR.sub.1 and --NH--R--C (O)--
or a combination thereof, wherein R is an alkylene group of at least about 2 carbon atoms, and R.sub.1 is R or aryl.
2. Description of Related Art
Application of a binder material to a substrate to increase its toughness, tensile strength and other physical properties is a technique well known in the art, as set forth, for example, in Olkers and Sweeney, Latex Binders and Binding Techniques for Disposable, TAPPI Proceedings, 1988 Nonwovens Conference, TAPPI Press, 1988.
The prior art with respect to non-formaldehyde binder systems has suggested use of urethane and acrylic polymers. For example, U.S. Pat. No. 2,837,462 to Van Norden Morin describes treatment of a nonwoven fabric with a binder comprising copolymers of vinyl acetate and an alkyl acrylate. The nonwoven fabric described in U.S. Pat. No. 4,207,367 to Baker is treated with a cross-linkable acrylic latex. U.S. Pat. No. 4,381,332 to Fulmer, et al. describes a nonwoven fabric treated with an elastomeric cross-linked polyurethane gel. The formaldehyde-free nonwoven binder material described in U.S. Pat. No. 5,030,507 to Mudge, et al. is treated with a binder comprising alkyl acrylates in combination with styrene, acrylonitrile, vinyl acetates and combinations thereof, isopropyl-.alpha.,.alpha.dimethyl benzyl isocyanate, and a multifunctional monomer.